Engine cut at Landing

[Greyhound]

My son has Revo with OS 21TM engine. He had couple run and the engine keep cutting at landing (only 2 feet jump) or cut at upside down landing. We can good idle and nice punch off line with wheelies. The temp is right at spot about 90-120 celcius. After 3 tanks, the engine refuse to fire up. I even over prime the engine and spinned it until it clear the flooded fuel, and still can't get it to start up.
What can cuase this? Thanks

 

[Metalhead Matt]

Sounds lean or the engine has an air leak. Check the obvious stuff first. Fuel lines, tank cap, header and coupler. If all that checks out, you should seal the engine before running it again.

 

[Greyhound]

Thanks Matt! I'd say the tune is on the rich side. I can tune HSN with no problem, but not quite ok with LSN. I can tell the lsn and turn to the right direction it when it's very obvious. I'll check the air leak by the weekend if I have a chance. The engine is only 7 tanks thru after break-in. If there is no air leak, and richen up lsn doesn't help. I'll seal the engine also. thanks again!

 

[Metalhead Matt]

Every engine should be sealed before running, really. Even a small leak will make tuning impossible. You wouldn't expect to have an air leak from the factory, but it happens. If you don't have a temp gun, get one when funds allow. If the engine is blowing smoke when accelerating, but still getting hot, it's either a lean lsn or an air leak.

 

[Greyhound]

Thanks Matt! I do have temp gun. I normally keep the engine temp below 110 celcius. I like OSengine at 90 celcius. I normally seal the engine before, but getting lazy and time is not permit me to do that anymore. I'll have someone at the hobby shop done for me, just in case anyway. Many thanks.